Question

What is one molar volume of the gas ammonia (nh3) at stp?

Answer 1

The molar volume of ammonia at standard temperature and pressure (STP) is 22.4L. This is the standard molar volume of any gas at these conditions.

Answer 2

Answer:

22.4 L is incorrect,  the answer is a little  less than 22.4

Explanation:

Why, because ammonia is not and ideal gas, it is a real gas.

Any ideal gas, does have a molar volume of 22.4 L at STP

The ammonia, molecule is very polar, that is why we can do an ammonia fountain.  The ammonia molecules are attracted to each other. and therefore a mole of ammonia gas (NH3) will occupy less than the 22.4 L than an ideal gas such as an inert gas would occupy.

I am a retired H. S. teacher and taught chemistry and then advanced placement chem.   As a review, and skipping the details. here is an investigation we did at the beginning of the AP chem class.  I have never seen it in a textbook.

After the first day of class a volunteer group of students standardized HCL to 0.100N, , or I did it myself.

Did ammonia fountain.  Put a small amount of phenolphthalein in the water before doing the fountain , for the fun of it- getting the pink ammonia solution

Collected 100.0 ml of the ammonia solution, titrated it with the 0.100N HCL  

Used pH meters which were more accurate, because the pH transition of the phenolphthalein  is about 8 or 9 or above.  

Knowing the amount (number of HCl molecules used to titrate and the balanced equation shows we had an equal number of NH3 in the 100.0 ml that were titrated.  

Took a ratio to determine what volume a mole of NH3 would occupy and then adjusted that value to STP.  

Used the collective class results,  and found we had very good precision. but knowing the molar volume of an idea gas, we knew the mean value was somewhat  low.  The question for the next day was why?  Some students were able to determine (after prodding and drawing a picture of the molecule showing its polarity) ,that NH3 is not an ideal gas.